Gas-generating apparatus

ABSTRACT

Gas generator having a folded inflatable bag connected thereto, the generator having a plurality of pockets confining propellant. Electrical ignition devices ignite the propellant in two pockets first to release gas for deploying or partially expanding the folded bag. Propellant filled channels connect the two initially ignited propellant pockets to the remaining pockets for igniting the latter to release gas for inflating the bag to a desired pressure. A sublimable, vaporizable or decomposable powdered material capable of absorbing heat is provided in the device to absorb the heat produced by the burning propellant.

United States Patent Leising et al.

[541 GAS-GENERATING APPARATUS [72] Inventors: Maurice B. Leising,Clawson; Herman J.

Greif, Jr., Orchard Lake; James R. Kirberg, Walled Lake; Philip J.Willson,

Royal Oak, all of Mich.

[73] Assignee: Chrysler Corporation, Highland Park,

Mich.

[22] Filed: May 11, 1970 [21] Appl. No.: 36,020

[52] US. Cl ..23/281, 60/3947, 62/4, 102/39, 149/72, 149/73 [51] Int.Cl. ..B01j 7/00 [58] Field ofSearch ..23/281; 60/3947; 252/67-71; 62/4;123/183; 102/39; 149/72, 73

[56] References Cited UNITED STATES PATENTS 2,128,576 8/1938 White et al..149/72 X 2,423,427 7/ 1947 Payn et a1. 149/73 51 Mar. 7, 19722,779,281 l/l957 Maurice et a1 102/39 3,305,319 2/1967 Kowalick et al.3,515,518 6/1970 Halstead et al.

3,532,358 10/1970 Selwa et al 3,532,359 10/1970 Teague et al.....3,532,360 10/1970 Leising et al ..23/281 Primary Examiner-James H.Tayman, Jr. Attorney-Talburtt and Baldwin [57] ABSTRACT Gas generatorhaving a folded inflatable bag connected thereto, the generator having aplurality of pockets confining propellant. Electrical ignition devicesignite the propellant in two pockets first to release gas for deployingor partially expanding the folded bag. Propellant filled channelsconnect the two initially ignited propellant pockets to the remainingpockets for igniting the latter to release gas for inflating the bag toa desired pressure, A sublimable, vaporizable or decomposable powderedmaterial capable of absorbing heat is provided in the device to absorbthe heat produced by the burning propellant.

3 Claims, 4 Drawing Figures PATENTEDMAR 1:972 3,647,393 I SHEET 2 OF 2FTTIXA/Z/f GAS-GENERATING APPARATUS BACKGROUND OF THE INVENTION Thisinvention relates to a gas generator and inflatable bag device, and moreparticularly to such a device particularly adapted for use in automotivevehicles and having improved gas-generating and coolant materials.

Many types of gas source or generator and inflatable bag devicesparticularly adapted for use in automotive vehicles are known. Forexample, some of these devices employ a sealed cylinder of compressedgas connected directly or by a conduit to an inflatable bag mounted onthe interior of the vehicle. A sensing device is conventionally providedfor sensing rapid deceleration or change in velocity of the vehicle.Upon a predetermined change in vehicle velocity, such as upon impactwith another object, the sensing device causes a signal to be sent to anactuating device for breaking the seal on cylinder to release the gas tothe bag. The latter inflates and provides a cushion against which anoccupant may be thrown by the impact.

Many of the known types of devices of this class require rathercomplicated and large components. The cylinder, for example, containingthe compressed gas, is often relatively bulky. Moreover, the bags ofthese devices could rupture during inflation due to frictionalinterlocking of one portion of the bag with another portion thereof.Another type of device uses an ignitable propellant to release gas forinflating the bag and a coolant to cool the gases. The present inventionis an improvement in the latter type of device.

BRIEF SUMMARY OF THE INVENTION Briefly, this invention comprises a gasgenerator for an inflatable bag and the generator having a supply ofpropellant for expanding the bag, a supply of heat absorbing material toabsorb heat from the gases released by the ignited propellant, and asupply of oxidizing material.

One of the primary objects of this invention is to provide a gasgenerating device which is adapted to fully inflate the bag very rapidlyand without heating the same to a very high temperature after a signalrequesting inflation is transmitted to the device.

Another object of this invention is to provide a device of the classdescribed which generates the gas at a relatively low pressure andprevents such gas from heating the bag to a high temperature.

A further object of this invention is to provide a device of the typedescribed which permits the gas generator and an inflatable bag to belocated in close proximity to one another.

Still another object of this invention is to provide a device such asdescribed which inhibits bag rupture, particularly during initialinflating of the bag from a normally collapsed position.

Another object of this invention is to provide a device of the classdescribed which is relatively compact in construction.

A still further object of this invention is to provide a device of thegeneral type described which is simple and economical in constructionand efficient in operation.

Other objects and advantages will become apparent as the descriptionprogresses.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings, in whichone of various possible embodiments of this invention is illustrated,

FIG. I is a side elevation, certain parts being shown in section, of adevice constructed in accordance with this invention;

FIG. 2 is an expanded fragmentary view of FIG. 1;

FIG. 3 is a view generally similar to FIG. 1, showing the bag during theinitial stages of inflation; and

FIG. 4 is a view generally similar to FIG. 3 showing the final stages ofbag inflation.

Like parts are indicated by corresponding reference charactersthroughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, adevice utilizing a gas generator having the inflating and cooling meansof this invention is generally indicated at 1. It includes a gasgenerator 3, a coolant chamber 4 and an inflatable bag 5.

Gas generator 3 may include a main body member 7 having a plurality ofcavities or pockets 9 therein. As shown, the confining means or pockets9 are formed into two groups or sets generally designated 11 and 13.However, the number of groups and pockets may vary considerably withoutdeparting from the spirit of this invention.

As shown, each group 11 and 13 includes five pockets with one pocket 15being designated as the primary ignition pocket for the group and withthe other four secondary ignition pockets 9 being arranged around theprimary ignition pocket. Propellant confining channels or grooves 17 areprovided in body 7 to join each of the pockets 9 in each group ofpockets with both the primary ignition pocket 15 and with the next ad-20 jacent secondary ignition pocket. In addition, each group of pocketsis interconnected to the other group of pockets by propellant confiningchannels or grooves 19 so that propellant, to be described hereinafter,ignited in one group of pockets may cause ignition of the propellant inall pockets.

Body 7 has recesses or bores 21 and 23 in which ignition devices 25 and27 are located. The ignition devices may take various forms, such asfuses, ignition squibs, or electrical igniters. As shown, the ignitiondevices are formed of electrical igniters having extension portions 26in smaller recesses 28 and two wire electrodes 29 and 31 joined togetherat the outer ends thereof by a tungsten filament 33.

The electrodes 29 and 31 and filament 33 of each igniter extend into theprimary ignition pocket of the respective group of pockets.

Each of the pockets 9 and 15 and the channels 19 are provided with asupply of propellant material 35 adapted, when ignited, to burn rapidly.Many sophisticated or exotic propellants such as rocket propellants areadapted to burn rapidly only when ignited under relatively highlypressurized conditions. Inasmuch as it is not desirable or practical toutilize highly pressurized chambers in devices of the type hereindescribed, such exotic propellants have not proved practical orreliable. However, the well-known propellant, commonly referred to asblack powder, will burn and undergo an exothermic reaction very rapidlyunder relatively low pressures. As is well known, black powder iscomposed of a mixture of the following materials in approximately thefollowing amounts:

Potassium Nitrate 75% Charcoal l 5% Sulfur l0% Generally speaking, thesmaller the granule size of the particles the faster the burning rate ofthe mixture.

While black powder, as described above, will perfonn in a satisfactorymanner to inflate a bag, it has been found that the hydrogen sulfideproduced by the reaction of the powder can be eliminated or reducedconsiderably if the sulfur content of the powder is reduced to the rangeof zero per cent to a maximum of two percent by weight of the totalcharge, with a mixture including approximately one-half percent sulfurby weight having been found to be particularly effective, for gasgenerators for inflatable bag devices. The remaining materials, i.e.,the potassium nitrate and charcoal may be changed from the above notedpercentages by weight to approximately percent and 28 percent-30percent, respectively, with approximately 29% percent by weight charcoalbeing satisfactory when the sulfur content is approximately k percent byweight.

A lower plate 37 is attached to body 7 by fasteners 39 extendingupwardly through the plate and the body. Extending across the uppersurface of body 7 over all of the propellant filled pockets is adiaphragm 40, such as an aluminum foil diaphragm, for example. A seconddiaphragm 41, such as a polyethylene diaphragm, for example. overliesdiaphragm 40 and underlies an upper plate 42 having holes 43therethrough vertically aligned with the pockets in body 7. Thediaphragms should be adapted to rupture when the pressure within eachpocket reaches a relatively low predetermined value. such as, forexample, 150 psi. This pressure value of 150 psi. is only exemplary andthe rupture pressure value could be higher or lower if desired.

A confining member or ring 45 may be located on top of plate 42 andforms part of a chamber 47 for holding a supply pf sublimable,vaporizable or decomposable material 49 capable of absorbing heat. Ithas been found that two compounds, ammonium oxalate and ammoniumformate, are particularly suited for use as solid coolants in gasgenerating devices for inlflatable bag devices. One consideration givento the selection pf a proper coolant in this type of device is thepressure producing characteristics of the material when subjected totemperatures of 180 or so. It is possible that such a temperature mightbe reached in a car parked in the sun on a hot day, for example, It hasbeen found that ammonium oxalate, for example, produces only a few psi.at a temperature of 180 F.

in addition to the use of a coolant it has been found desirable toinclude a certain amount of oxidizer 49a with the coolant. This oxidizeraids in reducing toxicity and reduces the amount of propellant requiredto produce a given amount of gas. In particular it has been found thatpotassium perchlorate has performed well as an oxidizer in a gasgenerator apparatus for an inflatable bag. The amount of coolant andoxidizer used in a device can, of course, vary depending on manyfactors, such as, for example, the size of the bag which is to beinflated. However, in a device utilizing approximately twenty grams ofpropellant, we have found that a 14.5 gram supply of ammonium oxalateand a 3.9 gram supply of potassium perchlorate mixed together andlocated in chamber 45, provide a component package which results insatisfactory performance. Thus, a complete material package includesabout 50 percent propellant by weight, 40 percent coolant by weight andpercent oxidizer by weight, the coolant and oxidizer being packagedtogether.

A third diaphragm 51, such as a polyethylene diaphragm, covers thechamber 47 and is held against ring 45 by a plate 53. Plate 53 has aplurality of holes 55 therein to permit the egress of propellant andmaterial 49.

Bag is folded in a manner to provide a plurality of folds 57 thereinlocated side-by-side and extending generally away from the generator.The outer edge or edges of the bag are folded double and secured to theperiphery of the plate 51 by a ring member 59 clamped on the foldededges by fasteners .39. The bag is preferably formed of a flexible wovensheet material combined with a rubber material. As will be made apparenthereinafter, the folding of the bag in the manner sub stantially permitsfree expansion of the bag without frictional interlocking of the bagmaterial during initial stages of inflation.

Assuming the bag is in the position shown in FIG. 1, operation of thedevice of this invention is as follows:

iElectrical current is supplied to each of the ignition devices .23 and25 through the wires connected thereto from a source tnot shown) such asan automotive vehicle battery, for example. The current would besupplied in response to a signalling device adapted, for example, tosense an abrupt change in velocity of the vehicle, such as upon impactwith another obyect.

When the current passes through the filaments 33, the powder in each ofthe primary ignition pockets l5 ignites and begins burning. As usedherein, the terms burn or burning mean a reaction which produces orreleases gas and heat. A pressure of I50 p.s.i., for example, is rapidlyattained, i.e., within a few milliseconds, and this pressure rupturesthe diaphragms 40 and 41 over the area of the primary ignition pockets.The powder in the primary ignition pockets which has not burned by thetime the diaphragms 40 and 41 rupture, llS propelled or thrown, due tothe 150 psi. gas in the pockets,

first into the chamber 47 where it mixes with the materials 49 and 49aand then through diaphragm 51 into the bag and continues to burn. Thematerial 49 absorbs a significant portion of the heat produced by theburning propellant, both in the chamber 47 and in the bag 5. Thematerial 49a reduces the amount of powder needed to inflate the bag.Moreover, when the material 49 vaporizes, it also releases additionalgas for inflating the bag. This initial delivery of gases and burningpowder into the bag causes the latter to be thrown into a partiallyexpanded position as generally shown in FIG. 3. Thus, the bag is throwninto this partially expanded position by considerably less than the fullforce which would be exerted thereon if all of the powder-filled pocketswere ignited simultaneously. If the latter condition occurred, two ormore of the folds of the bag might be forced together inhibiting bagexpansion and resulting in unusually instantaneous pressure which couldrupture the bag. The powder may, depending on its burning rate and timeof ignition, continue to burn after inflation to maintain the bag insuch condition and prevent deflation due to cooling of the gases.

While the bag is being thrown into the partially expanded position, thepowder in the channels 17 from each of the primary ignition pocketsburns and ignites the powder in pockets 9 surrounding each of theprimary pockets. The diaphragm portions covering such remaining pocketsare quickly burst and the powder in such other pockets is also thrownthrough chamber 47 into the bag as the expanding gases expand the bag.The powder thrown into the bag continues to burn to create gas forcontinuing the inflation of the bag until the latter reaches a desiredpressure condition such as shown in FIG. 4. At the same time thematerial 49 which is mixed with the burning propellant vaporizes andabsorbs heat therefrom. As described previously, the absorption of heatcauses the material 49 to release gas for inflating the bag andachieving the desired pressure. The oxidizer 49a also mixes with thepropellant and reacts to cause more gas to be produced. The ability ofthe materials 49 and 49a to perform as described permits a reduction inthe amount of propellant necessary to achieve the desired pressure inthe bag.

if one of the ignition devices 25 should fail to ignite the propellantin the associated pocket 15, the pockets in the associated group ofpockets will still be ignited by the propellant in the channels 19interconnecting the two groups 11 and 13 of pockets.

The total time period between passing current to the ignition devicesand complete inflation of the bag is very short, such as 20-30milliseconds, for example.

in addition to the materials 49 mentioned previously, i.e., ammoniumoxalate and ammonium formate, other materials might be useable with thepropellant and oxidizer in a gas generating device of an inflatable bagsystem. For example, it IS believed that the following materials mightbe used in this apparatus with more or less satisfactory results:ammonium carbamate, ammonium acetate, ammonium tartrate, magnesiumoxalate, potassium sulfate, potassium bicarbonate, mono ammoniumphosphate, zinc oxalate, magnesium phosphate tdibasic), ammoniumcitrate, ammonium di-citrate, ammonium magnesium phosphate, ammoniummagnesium carbonate, ammonium oxalatoferrate, ammonium hydroxy L-malate,cobalt carbonyl, and ammonium zirconyl carbonate. The material 49 shouldbe capable of storage and should be relatively stable. It should producea fair volume of gas which is not too corrosive and is relativelynontoxic. Most of the materials set forth above have the additionaladvantages of being storable as a powder.

it is also contemplated that oxidizers other than potassium perchloratemay have application in this apparatus. For example, manganese dioxide,sodium perchlorate, ammonium perchlorate and barium nitrate may beacceptable as oxidizers in this apparatus.

The device may be placed in various locations on the interior of anautomotive vehicle, such as on the upper end of the steering column, forexample. If a vehicle impact is sensed, the

bag can be rapidly inflated to provide a cushion against which a vehicleoccupant may be thrown.

As mentioned previously, the device of this invention preferably employsthe use of a propellant, such as black powder having a low sulfurcontent, which is adapted to burn at very rapid rate under relativelylow pressures. Moreover, by providing for an initial ignition andburning of some particles of the total propellant, followed byignitionand burning of the remaining particles of propellant, rupturing of thebag may be avoided. Furthermore, the material 49 inhibits or limits thetransfer of heat from the propellant gases to the walls of the bag 5.

In view of the foregoing, it will be seen that the several objects andadvantages of this invention are achieved.

Although only one embodiment of the invention has been disclosed anddescribed, it is apparent that other embodiments and modifications ofthe invention are possible within the scope of the appended claims.

We claim:

1. Inflatable device comprising a gas generator and an inflatable bagconnected to said gas generator, said gas generator having firstconfining means for holding a first supply of propellant, a first supplyof propellant in said first confining means, ignition means connected tosaid generator for igniting said first supply of propellant, secondconfining means for holding a second supply of propellant, a secondsupply of propellant in said second confining means, third confiningmeans for holding a third supply of propellant, a third supply ofpropellant in said third confining means, said third confining meansinterconnecting said first and second confining means, rupturable meanscovering said first and second confining means normally to prevent theegress of propellant therefrom, fourth confining means over said first,second and third confining means for holding a supply of materialcapable of absorbing heat, a supply of material capable of absorbingheat in said fourth confining means, said rupturable means covering saidfirst confining means rupturing when the pressure of the gases releasedby the ignited propellant in said first confining means reaches apredetermined value, the gases released by the ignited propellant insaid first confining means inflating said bag to a partially inflatedcondition, said propellant in said first confining means igniting saidpropellant in said third confining means which ignites said propellantin said second confining means, the gases released by the ignitedpropellant in said second and third confining means causing the meanscovering said second confining means to rupture and causing said bag tobe inflated to a desired pressure, said propellant including potassiumnitrate and charcoal, the potassium nitrate and charcoal beingapproximately 98 percent by weight of the total weight of thepropellant, said supply of material being forced into said bag by thegases released by said ignited supplies of propellant and absorbing heatfrom said ignited propellant, said material being selected from thegroup of compounds consisting of ammonium for mate, ammonium acetate,ammonium tartrate, magnesium oxalate, potassium sulfate, potassiumbicarbonate, momo ammonium phosphate, zinc oxalate, magnesium phosphate(dibasic), ammonium citrate, ammonium dicitrate, ammonium magnesiumphosphate, ammonium magnesium carbonate, ammonium oxalatoferrate,ammonium hydroxy L-malate, cobalt carbonyl and ammonium zirconylcarbonate.

2. Inflatable device comprising a gas generator, an inflatable bagconnected to said gas generator, said gas generator having firstconfining means, propellant in said first confining means, secondconfining means, propellant in said second confining means, thirdconfining means, propellant in said third confining means, said thirdconfining means interconnecting said first and second confining means,said propellant being adapted to undergo a reaction, said propellant,when reacting, producing heat and releasing gases for inflating saidbag, means for causing said propellant in said first confining means toreact in response to a signal, the propellant in said first confiningmeans, when reacting, releasing gases to cause the initial deploymentand partial inflation of said bag, said propellant in said firstconfining means causing the propellant in said third confining means toreact and release gases, said propellant in said third confining meanscausing said propellant in said second confining means to react andrelease gases, the gases released by said reacting propellant in saidsecond and third confining means causing the inflation of said bag to adesired pressure, said propellant including potassium nitrate andcharcoal, the potassium nitrate and charcoal being at leastapproximately 98 percent by weight of the total weight of thepropellant, said confining means including means for preventing escapeof propellant gases from said first and second confining means into saidbag until the pressure of said propellant and gases thereunder reaches apredetermined value, said means for preventing escape of propellant andgases from said first confining means being adapted to rupture andpermit escape of said propellant and gases into said bag after saidpredetermined pressure is reached in said first confining means, andadapted to rupture and permitescape of said propellant from said secondconfining means after said predetermined pressure is reached in saidsecond confining means and coolant means in said device for mixing withsaid propellant for preventing some of the heat produced by saidpropellant undergoing reaction from being transferred to the walls ofsaid bag, said means in said device for mixing with said propellantbeing a compound selected from the group consisting of ammonium formate,ammonium acetate, ammonium tartrate, magnesium oxalate, potassiumsulfate, potassium bicarbonate, mono ammonium phosphate, zinc oxalate,magnesium phosphate (dibasic), ammonium citrate, ammonium dicitrate,ammonium magnesium phosphate, ammonium magnesium carbonate, ammoniumoxalatoferrate, ammonium hydroxy L-malate, cobalt carbonyl and ammoniumzirconyl carbonate.

3. Inflatable device comprising a gas generator, an inflatable bagconnected to said gas generator, said gas generator having confiningmeans, said confining means including first and second separate holdingmeans, passage means interconnecting said holding means with oneanother, propellant in said holding means and the passage means,rupturable means covering said first and second holding means normallyto prevent the egress of propellant therefrom, said propellant beingadapted to undergo a reaction, means for causing said propellant in saidfirst holding means to react in response to a signal, said propellant,when reacting, producing heat and releasing gases, said rupturable meanscovering said first holding means rupturing when the pressure of gasesreleased by said reacting propellant in said first holding means reachesa predetermined value, said gases upon being released from said firstholding means initially deploying and partially inflating said bag, saidpropellant in said first holding means causing the propellant in saidpassage means to react, said propellant in said passage means causingsaid propellant in said second holding means to react, said rupturablemeans covering said second holding means rupturing when the pressure ofgases released by said propellant in said second holding means and saidpassage means reaches a predetermined value, said propellant in saidsecond holding means and said passage means, when reacting, releasinggases to further inflate said bag to a desired pressure, said propellantincluding potassium nitrate and charcoal, the potassium nitrate andcharcoal being at least approximately 98 percent by weight of the totalweight of the propellant, means in said device for mixing with saidpropellant for preventing some of the heat produced by said propellantundergoing reaction from being transferred to the walls of said bag,said means for mixing with said propellant for preventing some of theheat produced by said propellant from being transferred to the walls ofsaid bag being selected from the group consisting of ammonium formate,ammonium acetate, ammonium tartrate, magnesium oxalate, potassiumsulfate, potassium bicarbonate, mono ammonium phosphate, zinc oxalate,magnesium phosphate (dibasic), ammonium citrate, ammonium dicitrate,ammonium magnesium phosphate, ammonium magnesium carbonate. ammoniumoxialatoferrate, ammonium hydroxy L-maiate. cobalt carbonyl and ammoniumzirconyl carbonate. and oxidizer material :&elected from the groupconsisting of potassium perchlorate,

manganese dioxide and sodium perchlorate. 5

2. Inflatable device comprising a gas generator, an inflatable bagconnected to said gas generator, said gas generator having firstconfining means, propellant in said first confining means, secondconfining means, propellant in said second confining means, thirdconfining means, propellant in said third confining means, said thirdconfining means interconnecting said first and second confining means,said propellant being adapted to undergo a reaction, said propellant,when reacting, producing heat and releasing gases for inflating saidbag, means for causing said propellant in said first confining means toreact in response to a signal, the propellant in said first confiningmeans, when reacting, releasing gases to cause the initial deploymentand partial inflation of said bag, said propellant in said firstconfining means causing the propellant in said third confining means toreact and release gases, said propellant in said third confining meanscausing said propellant in said second confining means to react andrelease gases, the gases released by said reacting propellant in saidsecond and third confining means causing the inflation of said bag to adesired pressure, said propellant including potassium nitrate andcharcoal, the potassium nitrate and charcoal being at leastapproximately 98 percent by weight of the total weight of thepropellant, said confining means including means for preventing escapeof propellant gases from said first and second confining means into saidbag until the pressure of said propellant and gases thereunder reaches apredetermined value, said means for preventing escape of propellant andgases from said first confining means being adapted to rupture andpermit escape of said propellant and gases into said bag after saidpredetermined pressure is reached in said first confining means, andadapted to rupture and permit escape of said propellant from said secondconfining means after said predetermined pressure is reached in saidsecond confining means and coolant means in said device for mixing withsaid propellant for preventing some of the heat produced by saidpropellant undergoing reaction from being transferred to the walls ofsaid bag, said means in said device for mixing with said propellantbeing a compound selected from the group consisting of ammonium formate,ammonium acetate, ammonium tartrate, magnesium oxalate, potassiumsulfate, potassium bicarbonate, mono ammonium phosphate, zinc oxalate,magnesium phosphate (dibasic), ammonium citrate, ammonium dicitrate,ammonium magnesium phosphate, ammonium magnesium carbonate, ammoniumoxalatoferrate, ammonium hydroxy L-malate, cobalt caRbonyl and ammoniumzirconyl carbonate.
 3. Inflatable device comprising a gas generator, aninflatable bag connected to said gas generator, said gas generatorhaving confining means, said confining means including first and secondseparate holding means, passage means interconnecting said holding meanswith one another, propellant in said holding means and the passagemeans, rupturable means covering said first and second holding meansnormally to prevent the egress of propellant therefrom, said propellantbeing adapted to undergo a reaction, means for causing said propellantin said first holding means to react in response to a signal, saidpropellant, when reacting, producing heat and releasing gases, saidrupturable means covering said first holding means rupturing when thepressure of gases released by said reacting propellant in said firstholding means reaches a predetermined value, said gases upon beingreleased from said first holding means initially deploying and partiallyinflating said bag, said propellant in said first holding means causingthe propellant in said passage means to react, said propellant in saidpassage means causing said propellant in said second holding means toreact, said rupturable means covering said second holding meansrupturing when the pressure of gases released by said propellant in saidsecond holding means and said passage means reaches a predeterminedvalue, said propellant in said second holding means and said passagemeans, when reacting, releasing gases to further inflate said bag to adesired pressure, said propellant including potassium nitrate andcharcoal, the potassium nitrate and charcoal being at leastapproximately 98 percent by weight of the total weight of thepropellant, means in said device for mixing with said propellant forpreventing some of the heat produced by said propellant undergoingreaction from being transferred to the walls of said bag, said means formixing with said propellant for preventing some of the heat produced bysaid propellant from being transferred to the walls of said bag beingselected from the group consisting of ammonium formate, ammoniumacetate, ammonium tartrate, magnesium oxalate, potassium sulfate,potassium bicarbonate, mono ammonium phosphate, zinc oxalate, magnesiumphosphate (dibasic), ammonium citrate, ammonium dicitrate, ammoniummagnesium phosphate, ammonium magnesium carbonate, ammoniumoxalatoferrate, ammonium hydroxy L-malate, cobalt carbonyl and ammoniumzirconyl carbonate, and oxidizer material selected from the groupconsisting of potassium perchlorate, manganese dioxide and sodiumperchlorate.